Baked goods dough and method



United States Patent 3,368,903 BAKED GOODS DOUGH AND METHOD Robert H.Johnson and Eileen A. Welch, Norwalk, Conn., assignors to R. T.Vanderbilt Company, Inc., New York, a corporation of New York NoDrawing. Continuation-impart of application Ser. No. 274,068, Apr. 19,1963, which is a continuation-in-part of application Ser. No. 191,878,May 2,1962. This application Feb. 18, 1966, Ser. No. 532,045

Claims. (CI. 99-91) ABSTRACT OF THE DISCLOSURE A lipase preparationexhibiting activity in the pH range of 4.0 to 6.5, substantially freefrom deleterious amounts of proteinases, amylases and reducingsubstances, and which has the ability to increase the extractablemonoglyceride content of a dough is added to a dough to retard thetendency of the baked goods obtained from the dough to become stale.

This application is a continuation-in-part of our copending applicationSer. No. 274,068, filed Apr. 19, 1963, now abandoned, which, in turn, isa continuation-in-part of our application Ser. No. 191,878, filed May 2,1962, now abandoned.

This invention relates to the production of improved baked products andmore particularly to the production of bread, rolls and sweet goods thatremain soft longer.

It has been established by marketing research that the housewifecommonly selects bread on the basis of softness. A hard or firm feelingloaf of bread she adjudges stale even though it may be less than twelvehours from the oven. As a consequence of this tendency, most commercialbakers do everything possible to make their products soft.

Stale bread is sometimes sold at a discount but even this does not use astores supply, and much of it is returned to the baker to be used asbread crumbs or sold as animal food. As such practices 'are wasteful andexpensive, the baker is always concerned with better ways of solving thestale-return problem.

Soft bread is commonly produced by keeping baking time to a minimum, byadjusting the formula used, and by mixing, fermenting and handling thedough in such a way that the gas formed by the yeast is held in smallcells having very thin cell walls. Mineral dough conditioners, maltsyrup and invert syrup are ingredients often used for impartingsoftness.

Staleness in bread is accompanied by a number of changes. The loafbecomes progressively firmer, the crumb feels firmer, drier and morefriable, and the flavor gradually changes. Rate of staling can bemeasured most satisfactorily by recording the increase in firmness ofthe crumb by some mechanical means, but methods measuring the decreasein ability of the crumb to absorb water and the decrease in its solublestarch content have also been used.

The actual mechanism of bread staling has been studied for nearly onehundred years and is still not definitely known. It was proved early,however, that st'aleness is independent of moisture content, since breadaged in completely moisture proof containers would still go stale. Latertheories pointed toward an exchange of water between the starch andgluten fractions of the bread as the causative factor. These theorieshave since been considered of doubtful accuracy. The most recent theorysuggests that staling is caused by a chemical or physical change in thestarch fraction alone. This theory together with the observation that aloaf of stale bread may be freshened by heating, indicates that breadstaling depends upon changes in the starch-water relationship. Thestarchwater relationship is known to change in starch pastes themselveswhich retrograde or setup with age. It is considered likely that thesame thing occurs in the partially gelatinized starch in a loaf ofbread.

In an effort to combat the bread staling problem, most baked goods todaycontain one or more additives which, to a greater or lesser extent, willretard staling. One such additive consists largely of monoglycerides.Although these materials provide improved results, they may giveundesirable changes in the cell structure of the bread. This is oftenassociated with the use of monoglycerids made from fats having a highiodine number. The effect is more noticeable as the products containingmonoglycerides are permitted to age.

It has now been found that the use of certain lipase preparations in abread dough mixture will significantly retard the tendency of bread tobecome stale. At the same time, bread made in this manner exhibits noneof the disadvantages usually encountered when monoglycerides are used asbread staling retarding additives. The lipase preparation is added tothe bread dough along with flour, water, shortening, yeast and the otherconventional ingredients. The dough is mixed until smooth and isthereafter handled in the conventional manner.

Lipases are enzymes which accelerate decomposition of triglyceride fats.The decomposition products are mainly diglycerides, monoglycerides,fatty acids and glycerine, the relative amounts and proportions of eachdepending upon the characteristics of the lipase preparation and thelength of time over which it is permitted to act.

The lipases are individualistic in their behavior according to theirsource, conditions of preparation and use. Some produce an abundance ofone end product at the expense of another. Some lipases are moreeffective in acid medium while others are more effective with fattyacids of a particular type and are relatively or completely ineffectivewith others. Some may be crystallized as pure materials; others, asextensive trials have shown, are not pure materials but are mixtures ofactive components which are ineffective when separated. Most commerciallipase preparations contain, in addition to lipase, other types ofenzymes in appreciable quantities.

Lipase preparations which are useful according to this invention mustcontain lipases of the type which are capable of splitting triglyceridefats containing fatty acids having 12 or more carbon atoms. Also thelipase preparation must be one which is active at the pH of bread, whichgenerally ranges from 4.0 to 6.5.

The lipase preparations of this invention may contain minimum amounts ofextraneous active materials such as enzymes other than the lipases.Extraneous enzymes usually found in lipase preparations includeproteinases and amylases. Although these may be desirable for somepurposes, they are not essential to or related to the present invention.Lipase preparations also often contain reducing substances which aredetrimental and should be kept at a minimum level.

Proteinases of some types in proper quantity are of value in thepreparation of bread. Other types, on the other hand, are detrimental tobread quality. In selecting an appropriate lipase preparation, care mustbe taken to select one which does not have an excessive proteinaseactivity, as such preparations will provide a dough which becomes slimyand difficult to handle. Also, bread prepared with such preparationswill lack volume, may have a dark crust, and the crumb will have a poorcell structure.

The presence of high levels of amylase may impair bread quality becauseof its action in modifying the assaaos starches present. The internalstructure and color of the bread will be detrimentally affected and theamylase may cause crumbliness or stickiness in the bread.

Lipase preparations containing excessive amounts of reducing substanceswill impair bread quality. The bread will suffer most of the defects ofa bread prepared with lipase preparations containing excessive levels ofproteinuses. It is believed that the reducing substances may act asactivators of latent proteinases present in flour.

The lipase preparations of this invention are of benefit both in doughscontaining added fat as shortening and in those doughs which do not usean added shortening increment. Flour ordinarily contains about 1.5% oflipid materials, most of which can be extracted by solvents such asacetone or ether. It has been noted that once flour has been made intodough by the addition of water and mixing, the lipids apparently becomebound by the protein so that only about .15% of the lipids can beextracted by ether or acetone.

The use of the lipase prepartions according to this invention has asoftening effect when used in doughs having no added shorteningincrement. While the exact mechanism is not known, it is thought thatthe lipase splits the natural flour lipids to form monoglycerides, andthat these monoglycerides are, to some extent, preferentially bound bythe flour protein, displacing the lipid component. The increasedsoftness therefore is thought to be the added effect of themonoglyceride on the starch and the possible lipo-protein modifyingaction resulting from an increase in solvent-extractable lipids.

The following Examples 1 and'2 illustrate a method of preparing twopreferred lipase preparations for use according to this-invention.

EXAMPLE 1 Seeds from the plant Vernonia antlzelmintica, commonly knownas Indian ironweed, were used as a source of lipase enzyme. These seedsare described in the Journal of the American Oil Chemists Societyarticle by Krewson et 211., July 1962 issue, volume 39, No. 7, pages334-340. The seeds were processed to detach the hull from the endospermand separation of the two fractions was achieved by air classificationprocedures. The endosperm fraction was then ground to a fiour andimmediately extracted with petroleum ether to remove the oil presenttherein. The extraction process was continued until a maximum of 1% oilon a dry weight basis remained in the endosperm material. The resultingproduct was the color of a light rye flour and the flour particles weresoft and uniform in shape. This material, hereinafter described asdefatted ironweed flour, had a high lever of lipase activity.

The hull or bran fraction was extracted with petroleum ether in aseparate procedure until it contained a maximum of 1% oil on a dryweight basis. This material consisted of dark, hard, irregularly shapedparticles, and had a high level of lipase activity. This material willbe hereinafter described as defatted ironweed bran.

EXAMPLE 2 ENZYME PREPARATION-RAPESEED Twenty (20) grams of rapeseedswere ground in a mortar to a greasy paste. 100 ml. of distilled waterwere then added to the paste in small portions over a period of an hourwith frequent grinding. The material was then transferred to a beakerand 50 ml. of water added. The mixture was refrigerated overnight. Fiftyml. of phthalate buffer of pH 4.5 were added and the mixturecentrifuged. The cream was taken from the top of the tubes, washed withdistilled water and again centrifuged. 5.5 grams of a lipase cream wasobtained, which is hereinafter designated lipase preparation-Rapeseed(I).

A second lipase preparation was obtained from rapeseed in the mannerdescribed above, except that germiii nated seeds were used as thestarting material. This preparation will be hereinafter designated aslipase preparation-Rapeseed (II).

EXAMPLE 3 Each of the lipase preparations prepared in Example 2 above,i.e., Rapeseed (I) and Rapeseed (II), were added to bread doughs and thedoughs were oakcd. The breads obtained were compared with two controls,one a blank with no added enzyme or monoglyceride, the other with addedmonoglyccride but no added enzyme. A white pan bread was used in thistest, and was made according to the following.

Formula Sponge: Lbs. Hard wheat flour 60 Water 36 Yeast 2 Yeast food /4Dough:

Hard wheat flour 40 Water 25 Salt 2 Sugar 3 Dry milk 4 Shortening 2Lipase preparation Procedure Sponge-The yeast was dissolved in a portionof the water at 72 F., and the solution was added to a mixer along withflour, yeast food and the balance of the water. The materials were mixedjust enough to make a homogeneous mass, dumped into a trough andfermented for 5 hours at 72 F.

D0ug/z.--The fermented sponge was returned to the mixer, all of thedough ingredients were added and the batch was mixed until smooth. Thedough was allowed to stand about 15 minutes, divided, rounded andallower to stand again. It was then molded, panned, proofed at F. to thetop of the pans, and baked at 420 F. until uniformly brown, i.e., about30 minutes with steam in the oven. The loaves were cooled slowly to roomtemperature and wrapped in moisture proof paper.

Representative samples were taken immediately after baking and analyzedfor extractable monoglyceride content. Firmness of the resulting breadwas measured objectively after three days using a Baker Compressirneter.The results obtained are shown in the following table.

*ATMUL 122 is a commercially available ninnoglycoridc reaction productproduced by Atlas Chemicals Co. 1t contains 05 to 69% totalmonoglyceride, has not more than .594, free fatty acid, has meltingpoint 01' 125-127 F., and iodine value of 54-61 and is prepared fromanimal fat.

EXAMPLE 4 Defatted ironweed flour prepared according to Example 1 wasused in a bread made according to the procedure and formula set forth inExample 3. The bread prepared in this manner was substantially softerthan the control without lipase after 3 days of storage.

Defatted ironweed bran, also prepared according to Example 1, was usedin a bread made according to the procedure and formula set forth inExample 3. The bread prepared in this manner was substantially softerthan the control without lipase after 3 days of storage. However, thedefatted ironweed bran imparted a dark color and slightly bitter tasteto the bread. While the use of this material in white bread may beundesired for these reasons, it may be used in dark, strong-flavoredbreads where color and slight bitterness is not a problem.

It is noted that lipase preparations having similar crushed whole seed,followed by separation of bran levels of lipase activity may be preparedby defatting the and flour into separate fractions. In this event, theflour takes on some of the color and flavor of the hull or bran, and isuseful only for the purposes set forth above for the defatted bran.

The level of lipase useful in bread is determined by its potency underconditions of use and the amount and type of shortening used. Fromexperiments conducted thus far, amounts as small as 0.25 ounce of lipaseper 100 pounds of flour may produce a measurable decrease in the stalingrate.

The potency of a lipase is commonly expressed in terms of free fattyacids produced under standardized conditions. This, of course, is anindex of its ability to split a triglyceride but is not necessarily ameasure of its ability to produce monoglyceride. The value of lipase asan antistaling agent in bread is more closely related to its potencyexpressed in terms of monoglyceride production than expressed in termsof free fatty acid production. Accordingly, its effectiveness may begauged more accurately by the amount of extractable monoglyceride whichis in the bread product.

Effective amounts of lipase should produce an increase in extractablemonoglycerides of at least ounce per 100 pounds of flour. The maximumamount of lipase required depends on the reduction in firmness andstaling rate desired. In yeast raised sweet goods, for instance, theincrease in extractable monoglycerides may be as much as 32 ounces per100 pounds of flour.

Some monoglyceride is produced in bread during baking due to splittingof fats at elevated temperatures in the presence of water and salts.This monoglyceride may amount to 4 ounces per 100 pounds of flour. Thereis some evidence that this monoglyceride is formed too late in the breadmaking process to form anti-firming agents in bread. This monoglycerideis perhaps not available at a critical stage.

Whatever may be the effect of monoglyceride produced in the absence oflipase, it is clear that when lipase is added, more monoglyceride isproduced, and the desirable anti-firming effects are noticed with thefirst increase in extractable monoglyceride.

EXAMPLE 5 Bread was baked with increments of defatted ironweed flour todetermine its effect on third-day firmness and extractablemonoglyceride. The bread was prepared by the procedure and formula setforth in Example 3, except that 4 pounds of lard were used. Firmness wasmeasured by compression on an lntron testing machine. The bread wascompressed by 25% of original thickness. Force re- 6 EXAMPLE 6 Thedefatted ironweed flour prepared in Example 1 was used to make brewbread. Brew bread is a term used to include continuous mixed bread andthat made by batch processes wherein the major portion of fermentationoccurs in a brew. This is in contrast to conventional bread where themajor portion of fermentation occurs in a sponge. The essentialdifference between a brew and a sponge is the fact that the majorportion of the brew is water, generally -90% of total weight, whereas inthe sponge, water amounts to only 30-40% of total weight, the major partbeing flour. In this instance, the following formula and procedure wereused.

Brew: Parts by wt. Water 100.0 Dried yeast 1.65 Sugar 4.4 Salt 2.7Nonfat milk solids 6.6 Brew buffer 1 0.45

1 Manufactured by Standard Brands, Inc., and composed of calciumcarbonate, ammonium chloride, wheat flour, calcium sulfate and sodiumchloride.

The brew is fermented for about three hours while held at 8590 F. withagitation. Final pH should be about 5.3.

Dough: Parts by wt. Brew 52 Flour 100 Sugar 6 Salt 0.75 Shortening 4Water l8 Yeast 1 Defatted ironweed flour (as indicated below).

The dough was mixed and processed conventionally, in the mannerdescribed in Example 3. Bread was held at a uniform temperature in amoisture proof container. Firmness was measured on the third day.Extractable monoglyceride was determined as shown in the table below.

Defatted Defatted Control Ironweed Ironweed This exampie illustrates theuse of lipase preparations to improve the quality of bread to which noshortening has been added. The formula and procedure of Example 3 werefollowed, except that the shortening was omitted,

60 quired is given in arbitrary units. Extractable monoand the defattedironweed flour of Example 1 was used glyceride content is given asprecent of extractable llpldS, as a source of llpase. The results wereas follows: and in ounces per 100 pounds of flour. The results ob-Damned tained were as follows: Control Ironweed Flour DefatteExtractable Extractable Firrnness of bread, as percent of control afterIronweed Force Monoglvcende Mo ogly 3 days 100. 0 s3. 0 Flour, as ThirdDay as percent of in Ounces per Reduction f firmness, as percent f fipercent of Firmness Extra ta le 100 P s of ness of mm 0. 0 17. 0

Flour Llplds Flour Def-atted Ironweed flour as percent of weight offlour 0. 0 0. 30 Added Shortening 0.0 0.0 -00 955 Extractablemonoglyceri as percent of 015 890 2 0 weight of lipid extract 0. 190 0-700 875 2 Extractable lipids, as percent of weight of 06 745 7- 2 6flour 0. 130 0. 210 -125 720 9x2 Extractable monoglyceride, as percentof 25 645 8 3 flour 0. 024 0. 147

7 7 EXAMPLE 8 White pan bread was prepared according to the followingrecipes.

Procedure Sponge-The sponge was prepared by dissolving the yeast in aportion of the water at 110 F., and the solution was added to the mixeralong with flour, yeast food and the balance of the water. The materialswere mixed just enough to make a homogeneous mass, dumped into a troughand fermented for 3 hours at 78 F.

DuglI.-The fermented sponge was returned to the mixer, all of the doughingredients were added and the batch was mixed until-smooth. The doughwas allowed to stand about 15 minutes, divided, rounded and allowed tostand again. It was then molded, panned. proofcd at 95 F. to the top ofthe pans, and baked at 420 F. until uniformly brown, i.e., about 30minutes, with steam in the oven. The loaves were cooled slowly to roomtemperature and wrapped in moisture proof paper.

Representative samples were taken immediately after baking and analyzedfor extractable monoglyceride content. Firrnness of the resulting breadwas measured objectively after three days using a Baker Compressimeter.The results obtained are shown in the following table:

In the foregoing the lipase preparation used was obtaincd by cultivationof the microorganism Candida cy/indracea ATCC No. 14830 in accordancewith United States Patent No. 3,189,529 to Yamada et al., the disclosureof which is hereby incorporated by reference. As pointed out in thatpatent, lipase preparations may be prepared from Candida cylindracea No.14830 which has been cultivated in a suitable medium at 2035 C. In thesetests the lipase used had an activity of 21,000 u./g.

The enzyme unit is defined the amount of enzyme required to liberate 1mole of fatty acid per minute under the following conditions:

Into a glass-stoppered Erlenrnyer flask of 50 ml. capacity are placed 5ml. of an olive oil emulsion and 0.4 ml. of a 0.1 M phosphate bufferhaving a pH of 7.0. The olive oil emulsion is prepared by blending 22.9gm. of olive oil and 75 ml. of a 2% polyvinyl alcohol solution in ahigh-speed homogenizcr. The contents of the flask are mixed well andheated to 37 C. on a water bath.

To this solution 1 ml. of a sample solution containing a known amount ofa lipase preparation is added to the flask. The flask is shaken secondsto disperse the enzyme, and then incubated at 37 C. for minutes. Afterexactly 20 minutes, 20 ml. of a 50:50 acetone:

(ml. of NaOH for sample) (ml. of NaOll for blank X215 guns. of enzymeFor best results the amount of enzyme used in the foregoing test shouldbe sutlicient to yield a titration value of l.02.0 ml. of 0.05 N NaOH.

We claim:

It. A dough comprising flour and a lipase preparation, the lipasepreparation having the characteristics of exhibiting activity in the pHrange of about 4.0 to 6.5, being substantially free from deleteriousamounts of proteinases, amylases and reducing substances and having theability to increase the extractable monoglyccride content of the dough.

2. A dough comprising flour, shortening and a lipase preparation, thelipase preparation having the characteristics of exhibiting activity inthe pH range of about 4.0 to 6.5, being substantially free fromdeleterious amounts of proteinases, amylases and reducing substances andhaving the ability to increase the extractable monoglyceride content ofthe dough.

3. The dough of claim 2, wherein the lipase preparation is obtained froma material selected from the group consisting of ironwecd seed andrapeseed.

4. The dough of claim 2, wherein the lipase preparation is added in anamount sufficient to increase the extractable monoglyceride content ofbread prepared from said dough by at least 0.5 ounce per pounds offlour.

5. A dough in accordance with claim 2 comprising flour and a defattedironvced flour obtained from Vcrnonin anhtelmimica, the amount of saidironwecd flour being sufiicient to increase the extractablemonoglyceride content of said dough.

6. A dough in accordance with claim 2 comprising flour, shortening, anda defatted ironweed fiour obtained from Vcrnonia antliclmintica, thedcfatted ironweed flour being present in an amount sufiicient toincrease the extractable monoglyceride content 'of the dough, afterbaking, by at least 0.5 ounce per 100 pounds of flour.

7. A dough according to claim 2 wherein said lipase is obtained fromCandida cylimlracca ATCC No. 14830 which has been cultivated in asuitable medium at a temperature between 20 and 35 C.

8. A dough according to claim 2 comprising flour and a rapseed lipasepreparation, said preparation being present in an amount sufiicient toincrease the extractable monoglyceride content of said dough.

9. A dough according to claim 2 comprising flour, shortening and arapeseed lipase preparation, the lipase preparation being present in anamount sufficient to increase the extractable monoglyceride content ofthe dough after baking by at least 0.5 ounce per 100 pounds of flour.

10. In a method of preparing baked goods from a dough, the stepscomprising (1) the addition of a lipase preparation to said dough, thelipase preparation exhibiting activity in the pH range of about 4.0 to6.5, being substantially free from deleterious amounts of proteinases,amylases and reducing substances, and having the ability to increase theextractable monoglyceride content of the dough, (2) permitting thelipase to increase the extractable monoglyceride content of the dough,and (3) inactivating the lipase.

11. The method of claim 10, wherein the lipase preparation is obtainedfrom a material selected from the group consisting of ironweed seed andrapeseed.

12. The method of claim wherein the lipase preparation is present in anamount sufiicient to increase the extractable monoglyceride content ofthe *bread by at least 0.5 ounce per 100 pounds of flour.

1.3. In a method of preparing baked goods from a dough in accordancewith claim 10, the steps comprising (1) the addition of a defattedironweed flour obtained from Vernonia anthelmintica to said dough, (2)placing the dough under conditions permitting the lipase to act uponshortening to increase the extractable monoglyceride content of thedough by at least 0.5 ounce per 100 pounds of flour, and (3)inactivating the lipase.

14. In a method of preparing baked goods from a shortening-containingdough in accordance with claim 10, the steps comprising (1) adding arapeseed lipase preparation to the dough, (2) placing the dough underconditions permitting the lipase to act upon the shortening to in- 10crease the extractable monoglyceride content of the dough by at least0.5 ounce per 100 pounds of Hour, and (3) inacivating the lipase.

15. The method according to claim 10, wherein said lipase is obtainedfrom Candida cylindmcea ATCC No. 14830 which has been cultivated in asuitable medium at a temperature between and C.

References Cited UNITED STATES PATENTS 2,615,810 10/1952 Stone 99912,676,906 4/1954 Rose et al. l30 X 2,875,064 2/1959 Glabe 99-91 LIONELM. SHAPIRO, Primary Examiner.

JOSEPH M. GOLIAN, Examiner.

